Delphinium

Credit: Sharon Hanna

These Delphinium have snapped off in the rain and wind – but look pretty nice in a vase!

For many years, I have started Delphinium from seed in early summer. Homegrown ‘Pacific Giant’ types seem to last in my garden, but most consider them ‘short-lived’ perennials. Delphinium (from the Greek, i.e. the temple at Delphi – as individual flower buds resemble dolphins) attract beneficial insects like crazy – no wonder, as they have something nicknamed a ‘bee’ in the middle. This will be either dark or black, or grey to white – known as “black bee” or “white bee”.

Nothing quite equals a well-grown bunch of Delphinium in late May to mid-June; they’re most statuesque, but don’t do well in wind or too much rain (Vancouver, hello?), often flopping over and snapping, as their stems are hollow. For some reason I dislike supporting plants unless they are tomatoes or cucumbers – things vital to life. Non-food plants with few exceptions (OK, maybe sweet peas etc.) need to tough it out in my garden.

If you grow Delphinium in absolutely full sun, they’re unlikely to flop over unless it’s very windy or pours rain but giving them some support can’t hurt. Slugs love to eat the new shoots – try growing for the first few years in containers – they make a very nice specimen container plant and will grow huge.

Keep them away from the garden entirely until they’ve grown big. If you transplant a good-sized gallon pot size Delphinium in April into the soil, even a slug bite or two won’t do harm. Try coffee grounds in a ring around the plant – I don’t like to use any kind of “killers” in my garden. Just because I don’t understand a slug and why it’s there does not mean that it deserves to die – there’s a whole lot else I don’t know about as well…. And as the late Rita Ourum, worm lady extraordinaire, always said: slugs are every bit as useful as worms and I believe her.

Mid-June is usually perfect to start seed (freshly gathered or 1-2 years old max) in sterilized, loose starter mix, kept barely moist. Though this year, the Delphinium have not gone to seed because of our very cold spring! About 6-8 seeds per 5 cm (2 in.) cell is perfect – they’ll have room to grow without having to be transplanted right away. You can use bottom heat if you like, but they’ll be fine outside in a warm, sheltered place in dappled light, covered with a plastic dome – away from slugs, of course. You can start them as late as mid-July; depending on conditions, these may or may not bloom the following season whereas ones sown in June of this year are likely to flower next May or June.

Germination is variable, but usually about 10 days to 2 weeks. Seedlings grow quickly and will be ready for transplanting into 3-4 in. pots by mid-September, to winter over in a cool greenhouse. They’re relatively cold tolerant – down to about zone 4. Sometimes they lose their leaves, sometimes they don’t; it depends on weather conditions. They’ll come back strong in early spring. At that time, feed them something nutritious. Keep potting them up as needed.

Another hint: cutting back spikes after flowering (or snapping) will encourage a welcome second flush of blooms in late summer through early autumn.

If you need seeds, I could be willing to share! They’re mostly deep purple/blue – since they’re grown from seed, the colours are variable so there are sometimes exciting bi-colors and pale/dark blue mixes.